Force transmission mechanism for surgical instrument, and related devices, systems, and methods

ABSTRACT

An instrument includes a movable end effector component coupled to a shaft; a force transmission mechanism; and an actuation mechanism coupled to the force transmission mechanism and the end effector, the actuation mechanism comprising a first actuation member segment and a second actuation member segment. The force transmission mechanism comprises: a first pulley coupled to a rotatable drive input and having a first axis of rotation, and a second pulley having a second axis of rotation non-parallel to the first axis of rotation of the first pulley. The first actuation member segment is routed over the first pulley. In response to rotation of the rotatable drive input, at least a portion of the first actuation member segment is wound onto the first pulley and unwound from the second pulley, and the second actuation member segment is translated along the shaft to actuate the movable end effector component.

RELATED APPLICATIONS

This application is a continuation application of U.S. Application No.17/708,544, filed Mar. 30, 2022, which is a continuation application ofU.S. Application No. 16/083,150, filed Sep. 7, 2018 (now U.S. Pat. No.11,304,770), which is a U.S. national stage application under 35 U.S.C.§371(c) of International Application No. PCT/US2017/021284, filed Mar.8, 2017, which application claims priority to and the benefit of thefiling date of U.S. Provisional Pat. Application 62/305,867, filed Mar.9, 2016 (now expired), each of which is incorporated by reference hereinin its entirety.

TECHNICAL FIELD

Aspects of the present disclosure relate to a surgical instrument forcetransmission mechanism, configured to impart rotation and translationalmovement to an actuation mechanism coupled to an end effector of thesurgical instrument push/pull rod.

INTRODUCTION

Benefits of minimally invasive surgery are well known, and they includeless patient trauma, less blood loss, and faster recovery times whencompared to traditional, open incision surgery. In addition, the use ofteleoperated, computer-assisted surgical systems (e.g., robotic systemsthat provide telepresence), such as the da Vinci® Surgical Systemcommercialized by Intuitive Surgical, Inc. of Sunnyvale, Calif., isknown. Such teleoperated surgical systems allow a surgeon to operatewith intuitive control and increased precision when compared to manualminimally invasive surgeries.

Teleoperated surgical systems include one or more surgical instrumentsor tools. To perform actions directed by a surgeon, the teleoperatedsurgical system uses connections that permit motion of a surgicalinstrument, or a component on which a surgical instrument is mounted, inmore than one direction. In other words, the connection may be used toprovide more than one degree of freedom for the motion of a surgicalinstrument. Further, the connection may be used to translate motiveforce from an actuator to the medical instrument or to a component towhich the instrument is mounted. Thus, a connection may be required toprovide different functions and movements, even if these functions andmovements may otherwise conflict with one another from a mechanical orstructural sense.

SUMMARY

Exemplary embodiments of the present disclosure solve one or more of theabove-mentioned problems and/or demonstrate one or more of theabove-mentioned desirable features. Other features and/or advantages maybecome apparent from the description that follows.

In accordance with at least one exemplary embodiment, a forcetransmission mechanism for a teleoperated surgical instrument includes adrive pulley, a drive cable operably coupled with the drive pulley, adriven pulley operably coupled with the drive cable, and an actuationmember operably coupled to the driven pulley. The actuation member isconfigured to transmit force to actuate an end effector of the surgicalinstrument. Rotational motion of the driven pulley causes translationalmovement of the actuation element to actuate the end effector.

In accordance with at least one exemplary embodiment, a surgicalinstrument for a teleoperated surgical system includes a shaft, an endeffector disposed at a distal portion of the shaft, and a forcetransmission mechanism disposed at a proximal portion of the shaft. Theforce transmission mechanism includes a drive pulley, a drive cableoperably coupled with the drive pulley, a driven pulley operably coupledwith the drive cable, and an actuation member operably coupled to thedriven pulley. The actuation member is configured to transmit force toactuate an end effector of the surgical instrument. Rotational motion ofthe driven pulley causes translational movement of the actuation elementto actuate the end effector.

In accordance with at least one exemplary embodiment, a method ofoperating a surgical instrument includes winding a portion of a drivecable over a drive pulley by rotating the drive pulley responsive to atorque applied to the drive pulley, rotating a driven pulley byunwinding another portion of the drive cable from the driven pulleyresponsive to winding the portion of the drive cable over the drivepulley, translating an actuation element responsive to rotating thedriven pulley, and operating an end effector of the surgical instrumentresponsive to translating the actuation element.

Additional objects, features, and/or advantages will be set forth inpart in the description which follows, and in part will be obvious fromthe description, or may be learned by practice of the present disclosureand/or claims. At least some of these objects and advantages may berealized and attained by the elements and combinations particularlypointed out in the appended claims.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory onlyand are not restrictive of the claims. The claims should be entitled totheir full breadth of scope, including equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure can be understood from the following detaileddescription, either alone or together with the accompanying drawings.The drawings are included to provide a further understanding of thepresent disclosure, and are incorporated in and constitute a part ofthis specification. The drawings illustrate one or more exemplaryembodiments of the present teachings and together with the descriptionserve to explain certain principles and operation. In the drawings,

FIG. 1 is a front view of an exemplary embodiment of a patient side cartof a teleoperated surgical system;

FIG. 2 is a perspective view of an exemplary embodiment of a surgicalinstrument including a force transmission mechanism;

FIG. 3 is a schematic perspective view of an exemplary embodiment of aforce transmission mechanism coupled with an actuation member (shown inpartial view);

FIG. 4 is a perspective view of an exemplary embodiment of a forcetransmission mechanism and portion of a surgical instrument shaft;

FIG. 5 is a perspective view of various mechanical components of theforce transmission mechanism of FIG. 4 shown in isolation and coupledwith an actuation member (shown in partial view); and

FIG. 6 is a perspective view of an exemplary embodiment of a surgicalinstrument end effector coupled with an actuation member.

DETAILED DESCRIPTION

Various exemplary embodiments herein may be implemented using a daVinci® Surgical System (specifically, a Model IS4000, marketed as the daVinci Xi® Surgical System), commercialized by Intuitive Surgical, Inc.of Sunnyvale, Calif. Persons of ordinary skill in the art willunderstand, however, that inventive aspects disclosed herein may beembodied and implemented in various ways, including computer-assistedteleoperated and manual embodiments and implementations. Implementationson da Vinci® Surgical Systems are merely exemplary and are not to beconsidered as limiting the scope of the inventive aspects disclosedherein.

Various exemplary embodiments of the present disclosure contemplate aremotely-controllable surgical instrument having a force transmissionmechanism configured to convert input rotary motion to a translationalmovement of a push/pull rod, cable, or other actuation element.Exemplary embodiments of the present disclosure also contemplate such aforce transmission mechanism for a teleoperated surgical instrument.

FIG. 1 is a front view of the patient side cart 100 of a teleoperatedsurgical system. A teleoperated surgical system allows diagnostic andcorrective surgical procedures to be performed on a patient. Such ateleoperated surgical system is described in U.S. Pat. No. 8,545,515(filed Nov. 13, 2009), which is hereby incorporated by reference in itsentirety. The patient side cart includes a base 102 that rests on thefloor, a support tower 104 that is mounted on the base 102, and severalarms that support surgical tools (which can include a stereoscopicendoscope). According to an exemplary embodiment, surgical tools may bearranged according to the embodiments described in U.S. Pat. No.6,394,998 (filed Sep. 17, 1999) and U.S. Pat. No. 6,817,974 (filed Jun.28, 2002), which are hereby incorporated by reference in their entirety.

As shown in FIG. 1 , arms 106 a, 106 b are instrument arms that supportand move the surgical instruments used to manipulate tissue, and arm 108is a camera arm that supports and moves the endoscope. FIG. 1 also showsan optional third instrument arm 106 c. FIG. 1 further showsinterchangeable surgical instruments 110 a, 110 b, 110 c mounted on theinstrument arms 106 a, 106 b, 106 c, and an endoscope 112 mounted on thecamera arm 108, which may be interchangeable with a surgical instrument.A surgical instrument 110 a may be mounted to an arm 106 a via apatient-side manipulator (“PSM”) portion 120 that supports and moves thesurgical instrument.

FIG. 2 is a perspective view of an exemplary embodiment of a surgicalinstrument 200. As shown, the surgical instrument 200 includes a forcetransmission mechanism 210, an end effector 220 at a distal end 224 ofthe surgical instrument 200, and a shaft 222 connecting the forcetransmission mechanism 210 and the end effector 220. The surgicalinstrument 200 includes one or more members to translate force betweenthe force transmission mechanism 210 and the end effector 220. Forinstance, one or more actuation member(s) 226 may connect the forcetransmission mechanism 210 to the end effector 220 to provide actuationforces to the end effector 220, such as by extending through an interiorof the shaft 222. By utilizing actuation member(s) 226, the forcetransmission mechanism 210 actuates the end effector 220 to, forexample, control a jaw of the end effector 220 (or other moveable partof the surgical instrument). Further, because the end effector 220 maybe coupled to the shaft 222, force translated from the forcetransmission mechanism 210 to the end effector 220 may in turn betranslated to the shaft 222, such as when force transmission mechanism210 actuates end effector 220 in a rolling motion by rolling the shaft.

Actuation member(s) 226 may be in the form of tension elements, such aswhen the force transmission mechanism 210 is a pull-pull mechanism, orin the form of one or more force isolation rods, such as when forcetransmission mechanism 210 is a push-pull mechanism, such as a drive rodelement, as described in U.S. Pat. No. 8,545,515, referenced above.

The force transmission mechanism 210 may include one or more componentsto engage with a patient side cart 100 to translate a force provided bythe patient side cart 100 to the surgical instrument 200. According toan exemplary embodiment, the force transmission mechanism 210 mayinclude one or more interface disks 212, 214 that engage with the PSM120 of a patient side cart 100. Thus, interface disks 212, 214 maycouple with drive mechanisms (e.g., servomechanisms) (not shown) in thePSM 120 and translate a force from the drive mechanisms (e.g.,servomechanisms) to the surgical instrument 200. Thus, the interfacedisks 212, 214 utilize the actuation forces from the PSM 120 to actuatethe instrument 200 through the force transmission mechanism 210 andactuation member(s) 226. For instance, in an exemplary embodiment, thefirst disk 212 may be configured to provide a rolling motion to theshaft 222 and provide a roll degree of freedom (“DOF”) for the endeffector 220, while the second disk 214 may operate other DOFs of theend effector 220, such as, for example, to open and close a jawmechanism of the end effector.

Force transmission mechanisms, such as the force transmission mechanism210 of FIG. 2 , may be required to transmit relatively large forcesbetween the PSM 120 and the end effector 220 or other movable componentof the surgical instrument. For example, the end effector 220 may be inthe form of opposing openable and closable jaws such as are used inforceps, grippers, and clamps for closing ligation clips (i.e., a clipapplier), etc. Further, actuation of the end effector 220 may require alinear, translational movement of the member 226, e.g., when the member226 is a drive rod, while the movement of the interface disks 212, 214may be rotational movement. For these reasons, the force transmissionmechanism 210 may be required to convert the input rotational movementof at least one of the interface disks 212, 214 to generally linear,translational movement of a drive rod to actuate the end effector 220.Thus, it is desirable to provide a force transmission mechanism capableof efficiently transmitting relatively large forces between theinterface disks 212, 214 and the end effector 220, while at the sametime converting rotary motion of an interface disk to translationalmotion of a drive rod.

Referring now to FIG. 6 , an exemplary embodiment of an end effector 620is shown. The end effector 620 may be or include any of theconfigurations discussed above, such as a clip applier, forceps,grippers, etc. The end effector 620 includes first and second jaws 690and 691, respectively. The first and second jaws 690 and 691 arepivotally connected to a clevis 692 at a pivot, such as pinned joint693. A distal end of a drive rod 684 includes, or is attached to, a pin694 oriented orthogonally with respect to the drive rod 684. Statedanother way, the drive rod 684 and pin 694 provide a T-shapedconfiguration at the distal end portion of the drive rod 684. Movement(e.g., translation) of the drive rod 684 in the proximal direction(e.g., actuated by force actuation mechanisms 210, 310, or 410,discussed in connection with FIGS. 2, 3, and 4 respectively) causes thepin 694 to travel within cam slots 695 formed in cam extensions 696,697, respectively, of each of the jaws 690 and 691. Travel of the pin694 in the proximal direction through the cam slots 695 causes the pin694 to bear against the cam extensions 696, 697 within the slots 695,thereby move the jaws 690, 691 toward each other into a closed position.Movement (e.g., translation) of the drive rod 684 in the distaldirection causes the pin 694 to bear against the cam extensions 696, 697within the slots 695 to move the jaws 690, 691 away from each other andinto an open position.

Accordingly, exemplary embodiments of force transmission mechanisms ofthe present disclosure may be configured to transmit force between aninterface disk (e.g., interface disks 212, 214 of PSM 120) and an endeffector 220 or other distal movable component of a surgical instrument.In some exemplary embodiments, the force transmission mechanismsaccording to the present disclosure also convert rotational motion ofthe interface disk to translational movement of an actuation member(e.g., a drive rod).

Referring now to FIG. 3 , a simplified, schematic diagram of a forcetransmission mechanism 310 illustrates exemplary components andmechanical operation of an exemplary embodiment of a force transmissionmechanism. Other exemplary embodiments of force transmission mechanisms,such as the force transmission mechanism 410 described below inconnection with FIGS. 4 and 5 , may have similar mechanicalfunctionality to the force transmission mechanism 310, as well asadditional features and functionality. In the exemplary embodiment ofFIG. 3 , the force transmission mechanism 310 includes a drive pulley330, which may form a portion of a drive pulley assembly 458 as shown inFIGS. 4 and 5 , a driven pulley 332, and a drive cable 334 at leastpartially around each of the drive pulley 330 and the driven pulley 332.In some embodiments, the drive pulley 330 may be configured as acapstan. Rotational axes 336 and 338 of the drive pulley 330 and thedriven pulley 332, respectively, may be oriented in a parallel ornon-parallel relationship. In the exemplary embodiment of FIG. 3 , therotational axis 338 of the driven pulley 332 is oriented approximatelyperpendicular to the rotational axis 336 of the drive pulley 330 toimpart movement to an actuation element rod 348 along a desireddirection, as discussed below. In particular, in the orientation of FIG.3 the drive pulley 330 has a vertical axis of rotation and the drivenpulley 332 has a horizontal axis of rotation.

The drive cable 334 may be a single cable wrapped at least partiallyaround the drive pulley 330 and then connected at ends to the drivenpulley 332. Alternatively, the drive cable 334 may comprise two separatecables, each fixed at one end to the drive pulley 330 and at oppositeends to the driven pulley 332. Providing a drive cable 334 that has twoseparate cables may facilitate pre-tensioning of the drive cable 334, asdescribed in more detail below. The drive cable 334 is wrapped aroundthe drive pulley 330 such that a first portion 340 extends from thedrive pulley 330 towards the driven pulley 332 and a second portion 342extends from the drive pulley 330 also towards the driven pulley 332,but from a position on the drive pulley about diametrically opposite thefirst portion 340. As shown in FIG. 3 , the drive cable 334 wrapsmultiple times around the drive pulley 330 such that the portions 340and 342 extend from the drive pulley 330 at positions along the drivepulley that are separated by an axial distance. Respective ends of thefirst portion 340 and second portion 342 of the drive cable 334 arefixed to the driven pulley 332, and each portion 340 and 342 of thedrive cable 334 wraps around at least a portion of the driven pulley332. The drive cable 334 may be or include a single filament ofmaterial, or multiple filaments braided or twisted together. The drivecable 334 may comprise metal material such as stainless steel, atitanium alloy, tungsten, or other metals, or may comprise a polymermaterial or any other material having sufficient tensile strength andflexibility.

Rotation of the drive pulley 330 in direction 344 about the rotationalaxis 336 causes the first portion 340 to wind onto the drive pulley 330and the second portion 342 to pay out (unwind) from the drive pulley330. Tension generated in the first portion 340 imparts rotation of thedriven pulley 332 about the driven pulley rotational axis 338 indirection 346. As this occurs, the second portion 342 pays out from thedrive pulley 330 and winds onto the driven pulley 332.

Conversely, when the drive pulley 330 is rotated opposite the direction344 about the rotational axis 336, the second portion 342 of the drivecable 334 is wound onto the drive pulley 330, and the first portion 340pays out from the drive pulley 330. Tension in the second portion 342 ofthe drive cable 334 imparts rotation of the driven pulley 332 in adirection opposite direction 346, causing the first portion 340 to bewound onto the driven pulley 332 while the second portion 342 pays outfrom the driven pulley 332. In this manner, rotational motion of thedrive pulley 330 is transmitted via the drive cable 334 to the drivenpulley 332. Depending on the relative sizes of the drive pulley 330 anddriven pulley 332, and how the drive cable 334 is wrapped around each, atorque conversion may occur from the rotary input at the drive pulley330 to the rotary output at the driven pulley 332.

The driven pulley 332 may be operably coupled to a proximal end 350 ofan actuation element, such as a push-pull rod 348, a distal end (notshown in FIG. 3 ) of which is operably coupled with and configured toactuate a distal component of the surgical instrument, such as an endeffector, e.g., end effector 220 (FIG. 2 ) or end effector 620 (FIG. 6). As shown in FIG. 3 , the actuation rod 348 can be coupled to thedriven pulley 332 with, e.g., a joint such as a ball joint (not shown).Rotation of the driven pulley 332 about the rotational axis 338 causestranslational movement of the rod 348 along longitudinal axis 354 alonga proximal-distal direction, as the rotating driven pulley 332 applies aforce to the rod 348 through the ball joint 352. Translation of theactuation rod 348 actuates the end effector 220 (FIG. 2 ) or 620 (FIG. 6), as discussed herein in connection with FIGS. 2 and 6 .

FIG. 4 shows an exemplary embodiment of a portion of a forcetransmission mechanism 410. The embodiment shown in FIG. 4 may havefunctionality similar to that previously described and shown in FIG. 3 ,with specific features and aspects in addition to those discussed inconnection with FIG. 3 . For example, the force transmission mechanism410 may include a chassis 456 to which various components of the forcetransmission mechanism 410 are attached. While the chassis 456 is shownin FIG. 4 with mechanical components of the force transmission mechanism410 exposed for clarity, the chassis 456 may further include a cover(not shown) configured to engage with the depicted chassis to encloseand protect the mechanical components of the force transmissionmechanism 410 from foreign objects, contamination, etc. during use. Thechassis 456 may be configured to be attached to a PSM 120 (FIG. 1 ), andmay include interface disks (not shown) such as interface disks 212, 214(FIG. 2 ) configured to interact with mechanisms of the PSM 120.

An instrument shaft 422 is coupled to the chassis 456 at a proximal endof the instrument shaft 422. A distal end (not shown) of the instrumentshaft 422 includes an end effector, such as end effector 220 shown inFIG. 2 . The instrument shaft 422 may be configured to be rotatablerelative to the housing portion 456, e.g., based on a rotational inputto an interface disk, such as one of the interface disks 212, 214 (FIG.2 ). An actuation element, such as push-pull rod 348 (FIG. 3 ), extendsat least partially through the instrument shaft 422 and is configured toactuate the end effector positioned at the distal end of instrumentshaft 422, or another component of the instrument shaft 422. The rod mayactuate the end effector as it translates in the proximal-distaldirection described above in connection with FIGS. 2 and 6 .

The force transmission mechanism 410 includes a drive pulley assembly458 comprising a drive pulley (capstan) 430 rotationally coupled withthe chassis 456. A first drive cable 440 and a second drive cable 442are fixed at respective first ends to the drive pulley 430. The firstand second drive cables 440, 442 are fixed at respective second ends tothe drive pulley 430 and fixed at respective second ends to a drivenpulley 432. Rotation of the drive pulley 430 results in correspondingrotation of the driven pulley 432 in a manner similar to that describedabove in connection with FIG. 3 . Cable guides (e.g., fenders) 443ensure that the first and second actuator cables 440, 442 do not derailfrom idler pulleys 560, which are discussed further below in connectionwith FIG. 5 . The drive rod 348 is coupled with the driven pulley 432with a ball joint (not shown), discussed below in connection with FIG. 5. A retainer element 457 may retain the actuation member drive rod 348of FIG. 3 to the driven pulley 432.

Referring now to FIG. 5 , mechanical components of the forcetransmission mechanism 410 are shown without the housing 456 shown inFIG. 4 to simplify illustration of the various mechanical components.The drive pulley assembly 458 may include or be coupled with a driveinput disk 559, which may be meshed with a drive output disk (not shown)or otherwise rotationally coupled with one or more interface disks (suchas interface disks 212, 214 shown in FIG. 2 ) actuated by the PSM 120(FIG. 1 ) to rotate the drive pulley assembly 458.

The force transmission mechanism may include components configured toroute the first and second actuator cables 440, 442 between the drivepulley 430 and the driven pulley 432 and ensure that the actuator cables440, 442 wind on and off the drive pulley 430 and driven pulley 432correctly. For example, the force transmission mechanism may includeidler pulleys 560 about which the first and second actuator cables 440,442 are directed. As shown, for example, cable 442 extends over oneidler pulley 560 and cable 440 extends under the other idler pulley 560.The idler pulleys 560 may be positioned to ensure the first and secondactuator cables 440, 442 extend from the drive pulley 430 at anglessubstantially perpendicular to the rotational axis 536 of the drivepulley 430. Similarly, the idler pulleys 560 may be positioned to ensurethe first and second actuator cables 440, 442 extend from the drivenpulley 432 at angles substantially perpendicular to the rotational axis538 of the driven pulley 432. Such an arrangement may increase (e.g.,maximize) the force transmission capability of the force transmissionmechanism 410 by providing an optimal geometric relationship between theactuator cables 440, 442 and the drive and driven pulleys 430, 432. Sucha geometric relationship may reduce (e.g., minimize) loss. While theexemplary embodiment of FIG. 5 includes idler pulleys 560, othercomponents such as guides, pins, or any other routing device may be usedto align the actuator cables 440, 442 with the drive pulley 430 anddriven pulley 432 to optimize force transmission between the drive anddriven pulleys 430, 432.

The drive pulley 430 and the driven pulley 432 may include grooves 562,563 in which the actuator cables 440, 442 are seated to ensure theactuator cables 440, 442 remain routed correctly around the respectiveouter diameters of the drive pulley 430 and driven pulley 432. Thedriven pulley 432 may be rotationally coupled with the chassis 456 (FIG.4 ) with a pin 564. The pin 564 may be supported directly by the chassis456, or may rotate on plain bearings, ball bearings, roller bearings,etc. disposed within the housing 456. The drive pulley assembly 458 maybe mounted within bearings 565 disposed within the housing 456 (FIG. 4).

The first and second actuator cables 440, 442 may be fixed to the drivenpulley 432 by first crimping, soldering, or otherwise affixing enlargedends (only enlarged end 566 of the first actuator cable 440 shown inFIG. 5 due to perspective of the drawing) to ends of the first andsecond actuator cables 440, 442, and pressing the respective enlargedends into recesses 568 within the driven pulley 432. The first andsecond actuator cables 440, 442 are partially wrapped around the grooves562 of the driven pulley 432 and routed over the idler pulleys 560 asdescribed above.

According to an exemplary embodiment, the drive pulley assembly 458 mayinclude features configured to enable pre-tensioning of the first andsecond actuator cables 440, 442 during assembly of the forcetransmission mechanism. For example, in the exemplary embodiment of FIG.5 , the drive pulley 430 includes a lower sheave 570 and an upper sheave572. The lower sheave 570 and upper sheave 572 are configured to rotateindependently during a pre-tensioning operation (e.g., during assemblyof the force transmission mechanism 410), and to rotate together duringoperation of the force transmission mechanism. To achieve this, theupper sheave 572 includes a split collar 574 with a clamp screw 576 thatcan be tightened to rotationally lock the upper sheave 572 with thelower sheave 570. The first actuator cable 440 may include an enlargedend, such as barrel end 578, that can be crimped, soldered, welded, orotherwise fastened to an end of the first actuator cable 440. The barrelend 578 may be inserted within a recess 579 of the lower sheave 570,such that rotation of the lower sheave 570 winds a portion of the firstactuator cable 440 around the lower sheave 570. The driven pulley 432may be held in place while a torque is applied to the lower sheave 570to generate a tension in the first actuator cable 440. A similarenlarged end of the second actuator cable 442 (not shown due to theperspective of FIG. 5 ) may be inserted within a similar recess (alsonot shown) of the upper sheave 572, and the second actuator cable 442can be wound and pre-tensioned by rotating the upper sheave 572 in theopposite rotational direction relative to the pre-tensioning torqueapplied to the lower sheave 570. The clamp screw 576 is then tightened,rotationally locking the lower sheave 570 and the upper sheave 572together and maintaining the tension in both the first and secondactuator cables 440, 442.

In an exemplary embodiment, the driven pulley 432 includes a socket 580configured to accept a ball joint 582. The ball joint 582 connects tothe actuation (drive) rod 584 operably connected to an end effector(e.g., end effector 220 shown in FIG. 2 or end effector 620 shown inFIG. 6 ). The ball joint 582 and the drive rod 584 may be free to rotateabout a longitudinal axis of the rod 584 within the ball socket 580. Forexample, the instrument shaft 422 (FIG. 4 ) may be configured to rotatealong a longitudinal axis thereof in response to an input from one ormore interface disks, such as interface disks 212, 214 (FIG. 2 ). An endeffector (e.g., end effector 220 or end effector 620) may be coupled tothe end of the instrument shaft 422 and operably coupled with the driverod 584, e.g., such that translation of the drive rod 584 actuates theend effector as described above. The drive rod 584, the instrument shaft422, and the end effector may rotate in unison based on an input from aninterface disk. As the instrument shaft 422, end effector, and drive rod584 rotate, the ball joint 582 rotates within the ball socket 580. Sucha ball joint arrangement, and methods and devices for fastening the balljoint to the drive rod, are described in U.S. Pat. App. Pub. No. US2014/0338477 A1 (filed May 13, 2014), the entire disclosure of which isincorporated by reference herein.

The drive pulley 430 and the driven pulley 432 may be configured toprovide a mechanical advantage between the input to the drive pulleyassembly 458 (e.g., an input torque applied by a disk interface to thedrive pulley assembly 458 to actuate the force transmission mechanism)and the output to the end effector (e.g., end effector 220 (FIG. 2 ) or620 (FIG. 6 )). For example, a diameter of the drive pulley 430, adiameter of the driven pulley 432, and a distance of the ball join 582from the rotational axis of the driven pulley 432, may together define amechanical advantage to deliver a force sufficient to actuate the endeffector. For example, in an embodiment in which the end effector is ajaw mechanism configured to apply ligation clips, e.g., to blood vesselsof a patient, (e.g., the end effector comprises a “clip applier”), theend effector may require a force of up to approximately 45 pounds (45lbf; 200 N) to be delivered by the actuation rod 584, for example toclose the jaws as described above with reference to the exemplaryembodiment of FIG. 6 . The drive pulley 430 and the driven pulley 432may have different diameters to provide a desired mechanical advantagebetween an input to the drive pulley assembly 458 and an output of thedriven pulley 432. For example, a tensile force applied to the first orsecond drive cables 440, 442 by rotation of the drive pulley assembly458 may deliver a force at the actuation rod 584 equal to the tensileforce applied to the cables multiplied by a factor greater than one. Inan exemplary embodiment, the drive pulley assembly 458 is configured toapply a nominal tensile force of about 30 lbf to the first or secondactuator cable 440, 442 as each cable is wound around the drive pulleyassembly 458, and the mechanical advantage factor may be equal to about1.5, thereby delivering about 45 lbf/200 N to the actuation rod 584 toactuate the end effector. Other forces and factors of mechanicaladvantage as required by the specific application, type of end effector,etc. are within the scope of the disclosure, and the mechanicaladvantage may be tailored to the specific application by varying therelative size of the diameters of the drive pulley 430 and driven pulley432 and the distance from the rotational axis of the driven pulley 432to the ball joint 582.

In addition, the mechanical advantage provided by the force transmissionmechanism 410 may vary depending on the rotational position of thedriven pulley 432. For example, the mechanical advantage may be greatestwhen the ball joint 582 is horizontally aligned (in the orientation viewof FIG. 5 ) with the rotational axis 538 of the driven pulley 432, asthe length of an effective lever arm 586 acting on the ball joint 582 isat a maximum. Stated another way, the lever arm 586 is at a maximumeffective length when the lever arm 586 is orthogonal to both therotational axis 538 of the driven pulley 432 and the longitudinal axisof the drive rod 584. As rotation of the driven pulley 432 moves theball joint 582 away from the position of maximum effective length, amaximum force delivered to the end effector is reduced.

Accordingly, in exemplary embodiments, the rotational position of thedriven pulley 432 and the ball joint 582 may be optimized such that themechanical advantage delivered by the force transmission mechanism 410is at a maximum when the end effector or other actuated component of thesurgical instrument is in a position requiring the maximum appliedforce. For example, in embodiments in which the end effector comprises ajaw mechanism configured as a clip applier (see, e.g., FIG. 6 ), therequired force may be greatest when the jaws of the end effectorapproach a closed position. Consequently, the force transmissionmechanism may be configured such the lever arm 586 approaches themaximum effective length when the jaws of the end effector approach aclosed position. In other exemplary embodiments, such as embodiments inwhich the end effector is configured as forceps, grippers, or othertools, the position in which the lever arm 586 is at the maximumeffective length may or may not correspond to a closed position of thejaws of the end effector. For example, in an exemplary embodiment inwhich the end effector 220, 620 comprises a dissecting instrument, therotational position of the driven pulley 432 and the ball joint 582 maybe selected such that the mechanical advantage delivered by the forcetransmission mechanism 410 provides maximum force to open the jaws froma closed position. As an additional non-limiting example, with some endeffector tools, such as bipolar cautery forceps, a possibility existsthat tissue may stick to grippers of the tool, and thus requirerelatively high forces to open the tool. In such applications, themechanical advantage may be maximized for the force available to openthe tool over the force to close the tool, and the drive rod 584 andball joint 582 may be configured accordingly. Likewise, those ofordinary skill in the art would appreciate that force transmissionmechanisms may be configured to transmit maximum force over other rangesof motions when used to actuate other actuatable surgical instrumentcomponents, such as for example, articulatable wrist mechanisms, etc.

In exemplary embodiments, the actuation rod 584 may comprise a resilientmaterial configured to deform elastically in a transverse direction 588as the driven pulley 432 rotates. For example, in addition totranslational movement along the longitudinal axis of the actuation rod584, the ball joint 582 and the rod 584 near the ball joint 582 may bedisplaced along an arc as the driven pulley 432 rotates, the ball joint582 being constrained by ball socket 580 to a circular movement. Statedanother way, as the driven pulley 432 rotates clockwise as viewed inFIG. 5 , the ball joint 582 may move downward and slightly toward thedrive pulley assembly 458. However, the radius of the arc may berelatively large compared to the translational distance of the balljoint and rod along the longitudinal axis of the rod 584, and someelastic deformation of the rod 584 may permit movement of the ball joint582 along the arc as the rod 584 translates. Suitable materials for thedrive rod 584 may include relatively elastic materials such as stainlesssteel, titanium, nitinol, or other metal alloys, polymer materials, orother materials.

The force transmission mechanisms disclosed herein may be desirable overother configurations. For example, compared to various toothed geararrangements (e.g., helical gear and rack assembly), exemplaryembodiments of the disclosure exhibit lower friction and thus higherforce transmission efficiency. For example, in some situationsintermeshing toothed gear arrangements may exhibit 50 percent or lessforce transmission efficiency, due to frictional losses and lossesattributable to non-optimal geometry of the gear mating surfaces.Embodiments of the disclosure can exhibit force transmissionefficiencies above 50 percent, above 75 percent, etc. Additionally,embodiments of the disclosure can exhibit a range of motion of theactuation rod 584 greater than a range of motion obtainable with ahelical gear and rack configured to fit within a similar enclosure.Finally, under high applied torque, helical gears and componentssupporting and positioning the helical gears may deflect, allowing theintermeshing teeth of components (and actuation member) to momentarilydisengage and “skip” teeth, leading to misalignment of the mechanism,damage to gear teeth and other components, etc. Thus, embodiments of thedisclosure may promote the reliability and functionality of the forcetransmission mechanism, while permitting an overall compact size to beimplemented.

This description and the accompanying drawings that illustrate exemplaryembodiments should not be taken as limiting. Various mechanical,compositional, structural, electrical, and operational changes may bemade without departing from the scope of this description and theinvention as claimed, including equivalents. In some instances,well-known structures and techniques have not been shown or described indetail so as not to obscure the disclosure. Like numbers in two or morefigures represent the same or similar elements. Furthermore, elementsand their associated features that are described in detail withreference to one embodiment may, whenever practical, be included inother embodiments in which they are not specifically shown or described.For example, if an element is described in detail with reference to oneembodiment and is not described with reference to a second embodiment,the element may nevertheless be claimed as included in the secondembodiment.

For the purposes of this specification and appended claims, unlessotherwise indicated, all numbers expressing quantities, percentages, orproportions, and other numerical values used in the specification andclaims, are to be understood as being modified in all instances by theterm “about,” to the extent they are not already so modified.Accordingly, unless indicated to the contrary, the numerical parametersset forth in the following specification and attached claims areapproximations that may vary depending upon the desired propertiessought to be obtained. At the very least, and not as an attempt to limitthe application of the doctrine of equivalents to the scope of theclaims, each numerical parameter should at least be construed in lightof the number of reported significant digits and by applying ordinaryrounding techniques.

It is noted that, as used in this specification and the appended claims,the singular forms “a,” “an,” and “the,” and any singular use of anyword, include plural referents unless expressly and unequivocallylimited to one referent. As used herein, the term “include” and itsgrammatical variants are intended to be non-limiting, such thatrecitation of items in a list is not to the exclusion of other likeitems that can be substituted or added to the listed items.

Further, this description’s terminology is not intended to limit theinvention. For example, spatially relative terms - such as “beneath”,“below”, “lower”, “above”, “upper”, “proximal”, “distal”, and the like -may be used to describe one element’s or feature’s relationship toanother element or feature as illustrated in the figures. Thesespatially relative terms are intended to encompass different positions(i.e., locations) and orientations (i.e., rotational placements) of adevice in use or operation in addition to the position and orientationshown in the figures. For example, if a device in the figures is turnedover, elements described as “below” or “beneath” other elements orfeatures would then be “above” or “over” the other elements or features.Thus, the exemplary term “below” can encompass both positions andorientations of above and below. A device may be otherwise oriented(rotated 90 degrees or at other orientations) and the spatially relativedescriptors used herein interpreted accordingly.

Further modifications and alternative embodiments will be apparent tothose of ordinary skill in the art in view of the disclosure herein. Forexample, the systems and the methods may include additional componentsor steps that were omitted from the diagrams and description for clarityof operation. Accordingly, this description is to be construed asillustrative only and is for the purpose of teaching those skilled inthe art the general manner of carrying out the present teachings. It isto be understood that the various embodiments shown and described hereinare to be taken as exemplary. Elements and materials, and arrangementsof those elements and materials, may be substituted for thoseillustrated and described herein, parts and processes may be reversed,and certain features of the present teachings may be utilizedindependently, all as would be apparent to one skilled in the art afterhaving the benefit of the description herein. Changes may be made in theelements described herein without departing from the spirit and scope ofthe present teachings and following claims.

It is to be understood that the particular examples and embodiments setforth herein are non-limiting, and modifications to structure,dimensions, materials, and methodologies may be made without departingfrom the scope of the present teachings.

Other embodiments in accordance with the present disclosure will beapparent to those skilled in the art from consideration of thespecification and practice of the inventions disclosed herein. It isintended that the specification and examples be considered as exemplaryonly, with the following claims being provided their full scope ofbreadth, including equivalents, under the applicable law.

What is claimed is:
 1. An instrument comprising: a shaft; a movable endeffector component coupled to the shaft; a force transmission mechanismcoupled to the shaft proximally of the movable end effector component;and an actuation mechanism coupled to the force transmission mechanismand the end effector, the actuation mechanism comprising a firstactuation member segment and a second actuation member segment; whereinthe force transmission mechanism comprises: a rotatable drive input, afirst pulley coupled to the rotatable drive input and having a firstaxis of rotation, and a second pulley having a second axis of rotationnon-parallel to the first axis of rotation of the first pulley; whereinthe first actuation member segment is routed over the first pulley, andwherein, in response to rotation of the rotatable drive input: at leasta portion of the first actuation member segment is wound onto the firstpulley and unwound from the second pulley, and the second actuationmember segment is translated along the shaft to actuate the movable endeffector component.
 2. The instrument of claim 1, wherein the movableend effector component comprises a jaw assembly.
 3. The instrument ofclaim 2, wherein actuation of the movable end effector componentcomprises movement of the jaw assembly between an open position and aclosed position.
 4. The instrument of claim 1, wherein the first axis ofrotation and the second axis of rotation are orthogonal to one another.5. The instrument of claim 1, wherein the force transmission mechanismis configured to be coupled to a surgical manipulator.
 6. The instrumentof claim 5, wherein the rotatable drive input comprise an interfaceelement configured to engage the surgical manipulator to receive arotational force from the surgical manipulator.
 7. The instrument ofclaim 1, wherein the first actuation member segment comprises a cable.8. The instrument of claim 7, wherein the second actuation membersegment comprises a rod.
 9. The instrument of claim 1, wherein the shafthas a longitudinal axis parallel to the longitudinal axis of the firstpulley.
 10. The instrument of claim 1, further comprising an idlerpulley, wherein the first actuation member segment is routed over theidler pulley from the first pulley to the second pulley.
 11. A method ofactuating an end effector of an instrument, the method comprising:rotating a rotatable drive input of a force transmission mechanismoperably coupled to a first actuation member segment of an actuationmember; and in response to rotation of the rotatable drive input:winding the first actuation member segment onto a first pulley aboutwhich the first actuation member segment is routed and winding the firstactuation member segment from a second pulley having an axis of rotationnon-parallel with an axis of rotation of the first pulley; andtranslating a second actuation member segment of the actuation memberalong a shaft of the instrument to actuate a movable component of theend effector.
 12. The method of claim 11, wherein winding the firstactuation member segment onto a first pulley about which the firstactuation member segment is routed and from a second pulley having anaxis of rotation non-parallel with an axis of rotation of the firstpulley comprises winding the first actuation member segment from asecond pulley having an axis of rotation orthogonal to the axis ofrotation of the first pulley.
 13. The method of claim 11, wherein themovable component is a jaw assembly, and wherein the jaw assembly isactuated to move between an open position and a closed position.
 14. Themethod of claim 11, further comprising coupling the force transmissionmechanism to a manipulator system.
 15. The method of claim 14, whereinrotating the rotatable drive input of the force transmission mechanismcomprises rotating the rotatable drive input of the force transmissionmechanism with the manipulator system.